Re: Selenium formulas

Philip Jackson (pjackson@nla.gov.au)
Wed, 1 Nov 1995 12:16:05 +22303754 (EETDT)

I must admit I mixed some selenium toner not that long ago. Somebody gave
me a small jar of the powder, so away I went. My advice, however, is not
to chance it, but if you think you must, here are two formulas I got out
of an old book:

Kodak T-56 (sulphide-selenium toner for chloride and chlorobromide prints)
Bleach: Potassium ferricyanide 50 gm
Potassium bromide 50 gm
Water to make 1000 cc

Toning solution: Sodium sulphide (pure) 250 gm
Selenium powder 6 gm
Water to make 1000 cc

Some other formulas include ammonium chloride (purer whites?);
boric acid (less precipitate selenium) or substitue thiourea for
sulphide (less smell).

Kodak T-55 Selenium Toner
Stock solution: Sodium sulphite (crystalline) 300 gm
(or anhydrous) 150 gm
Selenium powder 6 gm
Ammonium chloride 190 gm
Dissolve sulphite in about 700cc of hot water; then add selenium; *boil*
until dissolved; cool; then add ammonium chloride, and water to 1000cc.
For use dilute 1 part stock to 5 parts water. Fix and wash prints; tone
10 to 15 min.; finally wash well before drying.

Kodak probably wouldn't want to see their name linked to these formulas
anymore; and I don't want to be held liable either. Once again, DON'T!

I tried the T-55 and found it virtually impossible to dissolve all the
selenium powder (all the while thinking how stupid boiling this stuff
was). In the end I decanted the solution off and discarded the sediment.
The sepias were nice enough, but even with a chorobromide papere there
were no hints of the gold toned albumen print purples I was after.

Although I haven't tried it, I think the thiourea variable warmth toner
is a much safer bet.

Philip Jackson
pjackson@nla.gov.au